Transistors have long been a bulwark of modem electronics due to their extreme reliability, ease of use, and high ON/OFF ratios of 104-105. Transistors are three-terminal devices that include source, drain, and gate electrode terminals. Two-terminal electronic devices, having only source and drain electrodes, typically have displayed much smaller ON/OFF ratios that have largely precluded their use in electronic switching and memory applications. However, such two-terminal electronic devices can be used in switching and memory applications, provided the devices can be made to display a non-linear current versus voltage response with sufficiently high ON/OFF ratios that are reproducible over operational cycling. In addition, two-terminal devices are desirable in electronics applications, since removal of the gate electrode terminal allows for continued device miniaturization to take place.
For many years, passive two-terminal electronic devices were thought to be limited to resistors, capacitors and inductors. However, based on theoretical considerations, a fourth two-terminal electronic device, a memristor, was proposed, and a nanoscale two-terminal electronic device having memristive properties was discovered in 2008. In macroscale devices, memristive effects are typically minimal. Simply put, a memristor is a passive two-terminal electronic device that continues to “remember” its last resistance state even when there is no bias voltage being applied to the device. On a more fundamental level, a memristor links the magnetic flux to charge. To function as a memristor, a two-terminal electronic device has to display a hysteresis in its current versus voltage profile.
Throughout the history of the semiconductor industry, silicon oxides [including silicon monoxide SiO, silicon dioxide SiO2 and non-stoichiometric silicon oxide SiOx (1<x<2)]] have long been considered to be a passive, insulating component in the construction of electronic devices. However, under appropriate conditions described herein, silicon oxides may become conductive and exhibit a hysteretic current versus voltage response. Such hysteretic behavior makes possible the construction of two-terminal electronic devices containing silicon oxides as a switching component. Such two-terminal electronic devices can be functional as memristors and other memory elements if their ON/OFF ratios can be made sufficiently high.
In view of the foregoing, two-terminal electronic devices containing silicon oxides exhibiting a hysteretic current versus voltage response would be of benefit in the electronics arts. Specifically, such two-terminal electronic devices may have functionality as memristors and other memory elements for switching and memory applications. In addition, two-terminal electronic devices containing silicon oxides are readily compatible with existing semiconductor manufacturing techniques, thereby facilitating their implementation in conventional electronics.